Can You Use Rice Water to Fertilize Houseplants? Experts Weigh In

It may not be as beneficial as you think.

Hand rinsing uncooked rice in a metal sieve with a jar of rice on the side — Credit:
alvarez / Getty Images

Rice water can help reduce water waste, but it’s not a reliable fertilizer for houseplants.
Rice water lacks key nutrients like nitrogen, phosphorus, and potassium, so it won’t replace a balanced fertilizer.
Use unsalted, fresh rice water sparingly to avoid soil buildup, bacteria, or fungi that can harm your plants.

If you spend any time on social media, you've probably come across houseplant tips and hacks. A common one is using rice water as a fertilizer for indoor plants. The idea is simple: After washing rice, use the leftover water on your plants to provide nutrients.

But does rice water actually have any benefits—and should you use it? We reached out to two experts to determine whether it works as a fertilizer.

Elin Harryson, plant expert at Planta
Justin Hancock, horticulturist at Costa Farms

Does Rice Water Provide Benefits?

The quick answer is no, rice water doesn't provide sufficient nutrients for your plants.

"It doesn’t contain enough nitrogen, phosphorus, or potassium to replace a balanced fertilizer," says Elin Harryson, plant expert at Planta.

In short, you may not be providing your plants with all the nutrients they need using rice water. "You shouldn’t think of it as a fertilizer source," says Justin Hancock, horticulturist at Costa Farms. "While it does contain starches released by cooking the rice, these starches don’t necessarily provide nutrients for the plants."

Should You Use Rice Water on Houseplants?

Rice water isn't a fertilizer, but you can still use it to water your plants. However, using it is more about reducing water waste, rather than providing your plants with nutrients.

"The amount of nutrients that leach out, once they’re broken down into a form your plants can use, is pretty negligible," says Hancock.

If you are going to use it, make sure that the rice water is unsalted, as salt can be detrimental to your houseplants. If you add salt, butter, or oil to rice, then don't use it on your houseplants. Hancock advises against using rice water on plants more than once a month.

Precautions

There are some downsides to watering your houseplants with rice water.

"The biggest drawback is using it too much [or] too often and having starches build up in your soil and attracting fungi or bacteria," says Hancock. Only use fresh rice water. Avoid saving it for later use, as the rice water can ferment and encourage bacterial growth.

Houseplants that are already wilting, suffering from root rot, or infested with pests shouldn't be watered with rice water, notes Harryson.